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F. T. BALDWIN. MillvPiok.

;N ..242,118. Patented May 31,1881.

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UNITED STATES PATENT OFFICE.

FRANKLIN T. BALDWIN, OF BALDWINSVILLE, ASSIGNOR OF ONE-HALF TO STEPHEN W. BALDWIN, OF NEI-V YORK, N. Y.

MILL-PICK.

SPECIFICATION forming piu-tof Letters Patent No. 242,178, dated May 31, 1881.

Application filed March .'30, 1881. (No model.)

To all whom it may concern:

Be it known that I, FRANKLIN T. BALDWIN, of the village of Baldwinsville, in the county of Onondaga and State of N ew York, have invented certain new and useful Improvements in Mill-Picks; andI do hereby declare that the following specitication, taken in connection with the drawings furnishedand forming part thereof, is a full, clear, and exact description Io of my invention. t

My invention relates to that class of millpicks which embody detachable points or cutters, and the object of my invention is to provide mill-pick points ot' light weight having three or more cutting-edges, and of such form as enables them to be rmly grasped in uniting them to the main body of the pick, and present an extensive abutting-surface for such contact with the body of the pick as will enazo ble a pick point and body when united to operate, practically, as it' the cutting-point and body were integral 5 and'the main feature of my invention consists in a detachable millpick point having three or more cutting-edges 2 5 and adapted to rotative adjustment in aholder, so that either of its edges may be used. The most desirable form of cutter-point devised by me is triangular in section, and has three cuttin g-ed ges.

3o Heretofore two-edged reversible and detachable pick-points have been employed; but my novel points canbe made of considerably less weight, and consequently more economically, andtheypossess one or more additional cutting- I 3 5 edges. My points are capable of being sharpened from time to time 5 .but they can be furnished at such low cost that, having been once dull, they may be thrown aside with economical results as compared with the cost of points 4o heretofore employed, which involve a greater weight of metal, two cutting-edges, and, of-necessity, more or less sharpening.

I am aware that aseries of mill-picks of practically the ordinary size and weight have been 4 5 so united in one piece as to form what may be termed a star-wheel,7 and that such have been so mounted in a handle that either of said picks could be used, as desired, by rotatively adjusting the Wheel in its handle; and I am 5o also aware that in stone-splitting machinery there has heretofore been employed, in connection with a stationary bed, a solid bar of steel of quadrangular form, and having` its angles constitute splitting-edges; but I know of no prior mill pick point having three or more cutting-ed ges, and adapted to be used in connection with a holder, as herein set forth.

My invention further consists in a mill-pick holder specially adapted to receive my novel cutters, whereby they are rmly clamped in 6o position and readily attached or removed.

As before herein indicated, I am well aware that holders of various forms have heretofore been used in connection with detachable points in mill-picks and in other stone-working tools, and that clamps have been therewith employed for connecting such points to the holders, and I will cite as an instance thereof the one'shown in United States Letters Patent No. 28,638, June 5, 1860; but I know of no holder prior 7o to my own in which a clamping-bar and a screw have been employed; nor do I know of any prior holder which would not require material changes in construction and arrangement to render them suitable for use with my detachable mill-pick points.

To more particularly describe my invention I will refer to the accompanying drawings, in which- Figure l represents, in side and end view, 8o one of Iny novel mill-pick points. Fig. 2 represents, in front view, my novel holder with the cutter-point detached. Fig. 3 represents the same in edge view, with the cutter-point in position. Fig. elis a modification of my holder adapted to receive a two-edged cutter-point. Fig. 5 is a sectional view of a cutter-point having four cutting-edges. Fig. 6 is a side view ot' one of my points provided with pickingpoints instead of plain cutting-edges: 9c

The detachable cutter-point A is composed of suitable steel rolled or forged and finished in a triangular form, so as to present the three cutting-edges a. The angles thus obtained are favorable to the production of astrong service- 9 5 able edge, and the quantity of metal in each point is so light as to enable the Whole to be hardened with practical uniformity and without diiculty.

The holder B is provided with the usual roe belve-eye b, and, being composed of steel, can be provided at one end with a cutting-edge, c. The opposite end of the holder is provided with an abutting surface, d, equal in length to the cutting-point used therewith, but slightly narrower, and has at one side an overlapping lip, e, between the inner side of which and the abutting surface a triangular recess is afforded for the reception ot' either edge of the triangular cutter-point. 0n the opposite side is a clamping-bar,f, having at one end a loose bearing in a sockenj", provided therefor in the side of the holder. This clamping bar may sometimes be so constructed as to be slightly yielding, after the manner 0l' a spring. A thumb-screw, g, is loosely housed in a bearing through the holder, and is tapped into a threaded hole through the clamping bar f. The outer end ot the clamping-bar is bent inward at an angle substantially corresponding with the angular sides of' the cutter A,so that when a cutter is placed in position, as shown, and the thumb-screw turned up the clamping bar not only forces the cutter laterally into the triangular recess, before referred to, but also, because ofthe angles involved, forces the eutter-point toward the abutting surface ot' the clamp and lirnily confines said cutter in worle ing position.

It will be seen that either one ot' the three cuttin g-ed ges a. may 4be employed, and that the clamp will as firmly confine the cutter in position after two ot' its edges have been used as before, and that the broad abutting surface bctween the holder and the cutter renders the two practically integral when properly clamped tingedge not iu use, in which case the augular lip and the angular end of the clampingbar (which I deem tobe novel features in this class ot' tools) will serve to draw the cutter toward the holder and firmly conueit,substan tially as with the novel triangular form, as ilinstr-ated in Fig. 4. The angles ot' the contactfaces of the lip and the clamping-bar should, of course, be made to correspond substantially with the angular sides of the cutter point, whether it have two or more cutting-edges.

lt will also be seen that in grinding my detachable cutters, if such bedeenied desirable, they have merely to be placed latlyon a grindstone, the grinding ot' each side serving for the partial development of two edges, thus requiring little or no skill inthe grinding operation. While I prefer the three-edged points, it is obvious that four edges may be provided on each point, as illustrated in Fig. 5, and that thejaws of' the holder may readily be adapted to properly engage therewith. For some purposes it is desirable to have one or more toothed edges on each point, as shown in Fig, 6. Havingthusdcscribed inyinvention, I claim as new and desire toiseenre by Letters Patentl. As a new article ot' manufacture, a millpick point having three or more cutting-edges,

and adapted to be rotatively adjusted in a holder, substantially as described.

2. A detachable mill-pick point triangular in cross-section, substantially as described.

3. The mill-pick holder provided with the angular recess, abutting surface, the clamping-bar, and screw, substantially as described.

4. In combination, the three-edged triangular detachable mill-pick point, and the holder provided with a belve-edge and littcd to receive and cla mp the saine, substantially as described.

FRANKLIN 'l. BALDWIN. Witnesses:

BERT D. J EssUP, FRANK P. TUGER. 

